1. Field of the Invention
The present invention relates to a power amplifier used for a mobile phone and the like.
2. Background Art
The power consumption of a power amplifier accounts for a high percentage of the entire consumption of a mobile phone. Accordingly, increase in efficiency of the power amplifier is important to reduce the power consumption. Thus, a power amplifier is adopted that switches between high and low output modes by means of a switch (e.g., see Japanese Patent Laid-Open No. 7-336168).